Payments on account forecaster
See what HMRC will ask you to prepay towards next year's tax bill, split between January and July.
Your payments on account
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Payments on account apply once your bill is over £1,000 and less than 80% of your tax was collected at source. Always take advice before acting.
How it works
If your Self Assessment bill is over £1,000, and most of your tax isn't already deducted at source, HMRC asks you to prepay towards next year's bill in two instalments: each worth half of this year's bill. The January payment combines your balancing payment for this year with the first payment on account for next year, so it's usually the larger of the two. The July payment is the second instalment on its own. Getting these dates and figures right is part of our self-assessment service, so there are no surprises in January.
Frequently asked questions
Why is my January bill so much bigger than July?
Because January combines the balancing payment for the year just finished with the first payment on account for the year ahead, roughly one and a half times your annual bill, while July is a single instalment.
Can I reduce my payments on account?
Yes, if you genuinely expect next year's bill to be lower, you can apply to reduce your payments on account. Reducing them too far can trigger interest if your actual bill turns out higher.
Do payments on account apply to everyone?
No, only if your last Self Assessment bill was over £1,000 and less than 80% of your total tax was collected through PAYE or another source at source.
What if my bill changes a lot year to year?
Payments on account are based on the previous year's bill, so a sharply rising or falling bill can mean you either underpay or overpay through the year, settled at the next balancing payment. Our self-assessment deadlines guide covers the full calendar this fits into.
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These results are a simplified illustration based on 2026/27 rates, not advice. Your real position depends on your full circumstances. For a personalised answer, book a free consultation.
Numbers looking complicated?
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